docs: def write_terminator(buff, capacity, ver, length):
      """\
      Writes the terminator.
  
      :param buff: The byte buffer.
      :param capacity: Symbol capacity.
      :param ver: ``None`` if a QR Code is written, "M1", "M2", "M3", or "M4" if a
              Micro QR Code is written.
      :param length: Length of the data bit stream.
      """
      # ISO/IEC 18004:2015 -- 7.4.9 Terminator (page 32)
      buff.extend([0] * min(capacity - length, consts.TERMINATOR_LENGTH[ver]))